Variation in the coding of the noncausal/causal alternation: Causative *-i in East Bantu languages

In this paper, we discuss shifts in the formal relation, i.e. “correspondence” (Haspelmath 1993; Nichols et al. 2004), between members of noncausal/causal verb pairs in eight East Bantu languages. These shifts are the effect of diachronic changes to the morphophonological structure of the verbs involved, conditioned by reflexes of a reconstructed Proto-Bantu causative suffix *-i. In the history of many Bantu languages, the high vowels i and u conditioned a series of sound changes on the preceding consonant. The suffixing of the causative suffix *-i to a verb root is one context in which these sound changes occurred. We investigate noncausal/causal pairs in eight East Bantu languages in which the causal verb is historically derived by a reflex of the suffix *-i. We argue that many of these noncausal/causal pairs changed from a causative to another correspondence. Our analysis has implications for the study of the formal alternations of noncausal/causal verb pairs across all Bantu languages and beyond.